RU2065733C1 - Device for external osteosynthesis - Google Patents

Abstract

FIELD: medical technology; external fixation of osseous transplant. SUBSTANCE: device has plate with holes for screws, holder attached to plate and made in form of comb with base of comb having ledge and hole for fixation to plate; teeth of comb are curved in form of arc and have salients within concave side. EFFECT: higher efficiency of procedure. 3 dwg

Description

 The invention relates to medicine, namely to traumatology and orthopedics, in particular, the treatment of fractures, nonunions and false joints with bone grafting.

 The Weber plate for bone osteosynthesis is known, having in the middle an element under the bone graft in the form of an arcuate bend outside (1).

Its disadvantages are:
compression of soft tissues over the convexity of the plate, which limits its use to a segment covered with a thick layer of muscles (thigh);
a small area of coverage with a bone graft, limited by the width of the plate.

 The closest analogue is a compression device for osteosynthesis (2), designed to hold a bone graft, made in the form of an outer and inner trough-like plates, while the inner plate is placed in the recess of the outer plate, and a cross-shaped plate spring is located between them. The outer plate is made with mounting holes, the plates are fixed to each other and with a spring by a pin.

The disadvantage of this device are:
high invasiveness of the operation, since a bed is formed under the bone graft in the surface and in the thickness of the bone wall, while the periosteum and part of the living bone tissue are lost;
limited transverse dimensions of the bone graft, since its thickness depends on the thickness of the bone wall in which the bed under the bone graft is formed;
a small area of coverage with a bone graft, limited by the width of a removable gutter-shaped plate.

 The technical result of the invention is to increase the effectiveness of bone grafting by increasing the coverage area of the transverse defect in the bone around the bone graft with a bone graft while reducing the invasiveness of the operation.

 This result is ensured by the fact that the device for bone osteosynthesis is made in the form of a plate with holes for screws, with a removable holder mounted on it. The holder is made in the form of a comb, the teeth of which are curved arcuate and have protrusions at their free ends from the concave side, and is also equipped with a base having a ledge and a hole for fixing on the plate.

 The invention is illustrated by drawings: figure 1 shows a General view of the device; figure 2 section bb in figure 1; figure 3 section aa in figure 1.

 The device for bone osteosynthesis has a plate 1, which can be any plate suitable for osteosynthesis of any tubular bone, a holder 2 made in the form of a comb with arcuately curved teeth 3, provided with protrusions 4 located on the concave side at the free ends of the teeth and used to provide reliability of fixation of bone grafts. The holder 2 has a base 5 with an opening 6 for attaching the holder to the plate and with a step 7, the height of which is less than the thickness of the plate, for example, 2 times. This provides a sufficient gap between the holder and the bone surface for placement of bone grafts 8. In addition, the angle of the step coincides with the angle of the plate, which provides resistance to rotational displacements of the connection between the holder and the plate. The number of teeth of the comb may be different, for example, equal to three. The gaps between the teeth are intended for vascularization of the plastic material and the underlying bone. The holding of bone grafts is ensured by the pressing force in the direction from the teeth of the comb to the bone surface due to the elasticity of the material from which the holder is made, for example, VTv titanium alloy. For this, during the operation, the teeth of the comb combs are modeled in an arc with a smaller radius than the radius of the circumference of the object at the level of the intended fixation. A shape memory material can also be used for the holder. To form a gap for a transplant of different thicknesses, the teeth of the comb are bent or bent to the surface of the bone. The magnitude of the curvature of the teeth is modeled due to plastic deformation of the material of which the holder is made.

 With the device they work as follows.

 After processing the false joint, nonunion, fresh fracture, the fragments are connected with the bone plate 1. The teeth 3 of the combs of the removable holder are bent. The bending radius varies depending on the thickness of the bone grafts. Bone grafts are placed on the bone surface at the defect level and pressed with a removable holder, the ledge 7 of which is aligned with the angle of the plate 1, and the hole 6 with the hole in the plate 1. Through the holes, the holder is fixed to the plate 1 and the bone.

 To fix a large fragment or fragments that after reposition do not fall into the medullary canal, the teeth of the comb 3 of the holder are modeled in a circle with a radius slightly smaller than the radius of the bone circumference at the level of the fragments. If a fragment or fragments after reposition fall into the medullary canal, then first fill the medullary canal at the level of the fragments with bone crumbs or bone graft, then perform the work described above.

 During bone grafting surgery, the periosteum is not scraped off, a bone groove is not made under the bone graft. This does not damage the periosteal and intraosseous blood circulation, the invasiveness of the operation is reduced. YYY2

Claims (1)

 A device for bone osteosynthesis comprising a plate with holes for screws and a removable holder mounted on the plate, characterized in that the removable holder is made in the form of a comb with a base having a ledge and a hole for fixing on the plate, and the teeth of the comb are curved arcuate and have free ends protrusions on the concave side.

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